1. Field of the Invention
The present invention is generally related to aluminum alloys and articles produced therefrom. More particularly, the present invention is related to aluminum-copper alloys exhibiting improved strength at room temperature and elevated temperatures.
2. Description of the Related Art
Aluminum alloys have long been used in the aerospace field due to their unique combination of strength and lightweight. However, the new generations of jet engines are becoming more efficient and generally run hotter than their predecessors. Therefore, titanium is increasingly being utilized more often for aerospace applications since conventional aluminum alloys do not generally provide sufficient strengths at the elevated operating temperatures of the newer jet engines.
Although there are many commercially available aluminum alloys that can be used in a variety of fields, many of these alloys have limited applications in the aerospace field due to their inability to exhibit ideal strengths at both room temperatures and the elevated operating temperatures of jet engines. For example, the 7000-series aluminum alloys generally exhibit high strength up to about 275° F., but quickly lose their strength at higher temperatures. In contrast, the 2000-series aluminum alloys typically exhibit higher strengths at elevated temperatures than the 7000-series, but exhibit lower strengths at room temperature and are prone to stress corrosion cracking.
U.S. Pat. Nos. 4,772,342; 5,055,256; 5,115,770; 5,259,897; 5,455,003; 5,512,112; 5,630,889; 5,665,306; 6,126,898; 6,368,427; 6,579,386; and 7,229,508; and U.S. Patent Application Publication Nos. 2006/0137783; 2011/0030856; and 2011/0176957, each of which are incorporated herein by reference in their entireties, describe various aluminum alloys containing different types of alloying additives. Although the various aluminum alloys described in these references may exhibit desirable traits sought in specific types of aluminum alloys, each exhibit at least one deficiency that do not make them ideal fir use in aerospace applications.
Accordingly, there is a need for an aluminum alloy for aerospace and aeronautical applications that exhibits a desirable strength portfolio at both room temperature and the elevated operating temperatures of jet engines.